B&S Welch plug.

I have only been doing service on four cycle engines for a short time and learning as I go and doing very well,for the most part.
Looking online without back and forth type communication can sometimes leave me with a quick yes or no type question.
Raining right now so I don't have the engine model in front of me.
Briggs and Stratton Quantum series.
Stupid primer bulb on the side.
Carburetor nasty so it is clean now but she won't start.
Took the carburetor back off to recheck things and when...

B&S Welch plug.